Lecca D, Nevin D K, Mulas G, Casu M A, Diana A, Rossi D, Sacchetti G, Fayne Darren, Carta A R
Department of Biomedical Sciences, University of Cagliari, Italy.
School of Biochemistry & Immunology, Trinity College, Dublin, Ireland.
Neuroscience. 2015 Aug 27;302:23-35. doi: 10.1016/j.neuroscience.2015.04.026. Epub 2015 Apr 20.
Peroxisome proliferator-activated receptor (PPAR)γ is a potential pharmacological target for disease-modification in Parkinson's disease (PD), mainly acting by modulating the neuroinflammatory response. However, currently available agonists thiazolidinediones (TZDs) present limitations due to safety concerns. We evaluated a novel thiobarbituric-like compound MDG548, which acts as a functional PPARγ agonist displaying higher and selective binding affinity as compared to TZDs. Neuroprotection by MDG548 was tested in vitro and in a mouse MPTP model of PD, and neuroinflammation was investigated as a putative underlying mechanism. Viability assay on rat cortical neurons showed lack of cytotoxic effect in the dose-range of 100 nM-10 μM, which was therefore used for testing in vitro protection against H2O2 and MPP+ neurotoxicity. MDG548 dose-dependently increased cell viability of rat cortical neurons co-treated with H2O2 or pre-exposed to MDG548 prior to H2O2. Moreover, MDG548 induced neuroprotection in MPP+-treated PC12 cells. NF-kB activation was investigated to assess anti-inflammatory activity. MDG548 dose-dependently decreased NF-kB activation induced by LPS (100 ng/100ml) in HEK-Blue-hTLR4 cells. Given the supposed cancer risk of other PPARγ agonists, Ames test for genotoxicity was performed in Salmonella typhimurium TA100 and TA98 strains, showing that MDG548 was not genotoxic. In vivo, BL/6J mice were treated with MPTP (20mg/kg i.p. once/day for 4 days) in association with saline or MDG548 (2, 5, 10 mg/kg i.p.). Stereological counting showed that MDG548 prevented the MPTP-induced reduction in TH-positive cells in the substantia nigra compacta (SNc) at all doses tested. Moreover, MDG548 reduced reactive microglia and iNOS induction in the SNc. MDG548, being a non-TZD compound with high PPARγ affinity, void of genotoxicity, and with in vitro as well as in vivo neuroprotective properties, provides a promising alternative in the search for safer PPARγ agonists to be tested as potential disease-modifying drugs in PD.
过氧化物酶体增殖物激活受体（PPAR）γ是帕金森病（PD）疾病修饰的潜在药理学靶点，主要通过调节神经炎症反应发挥作用。然而，由于安全性问题，目前可用的激动剂噻唑烷二酮类（TZDs）存在局限性。我们评估了一种新型硫代巴比妥类化合物MDG548，它作为一种功能性PPARγ激动剂，与TZDs相比显示出更高的选择性结合亲和力。在体外和PD小鼠MPTP模型中测试了MDG548的神经保护作用，并将神经炎症作为一种潜在的潜在机制进行了研究。对大鼠皮质神经元的活力测定显示，在100 nM - 10 μM剂量范围内没有细胞毒性作用，因此用于测试对H2O2和MPP +神经毒性的体外保护作用。MDG548剂量依赖性地增加了与H2O2共同处理或在H2O2之前预先暴露于MDG548的大鼠皮质神经元的细胞活力。此外，MDG548在MPP +处理的PC12细胞中诱导神经保护作用。研究了NF-κB激活以评估抗炎活性。MDG548剂量依赖性地降低了HEK-Blue-hTLR4细胞中由LPS（100 ng/100ml）诱导的NF-κB激活。鉴于其他PPARγ激动剂存在潜在的癌症风险，在鼠伤寒沙门氏菌TA100和TA98菌株中进行了Ames遗传毒性试验，结果表明MDG548没有遗传毒性。在体内，将BL/6J小鼠与生理盐水或MDG548（2、5、10 mg/kg腹腔注射）联合用MPTP（20mg/kg腹腔注射，每天一次，共4天）处理。立体学计数显示，在所有测试剂量下，MDG548均能防止MPTP诱导的黑质致密部（SNc）中TH阳性细胞的减少。此外，MDG548减少了SNc中反应性小胶质细胞和iNOS的诱导。MDG548作为一种具有高PPARγ亲和力、无遗传毒性且具有体外和体内神经保护特性的非TZDs化合物，为寻找更安全的PPARγ激动剂作为PD潜在疾病修饰药物进行测试提供了一个有前景的选择。
